Method and apparatus for depositing components on a substrate - Patents.com

Abstract

A deposition apparatus (1) for depositing components (CMP) on a substrate (STR) is provided. The deposition apparatus (1) includes a substrate holder (2), a component carrier (3), a power supply (4), and a support module (5) for supporting the component carrier (3). The substrate holder (2) has a substrate support surface (2s) for holding the substrate (STR). The component carrier (3) supported by the support module has a component carrier surface (3s) facing the substrate support surface (2s) for supporting a component to be deposited on the substrate. The component carrier (3) includes a resistive heater layer (31) for thermally inducing deformation of the component carrier (3) to move the component carrier surface (3s) toward the substrate support surface (2s). The power supply (4) is configured to generate a deflection pulse (Pd), which is a power pulse to the resistive heater layer (31) for thermally inducing the deformation. A corresponding deposition method is also provided.

Description

[Technical Field]

[0001] This application relates to a method for depositing components onto a substrate. The present application further relates to an apparatus for depositing components on a substrate. [Background technology]

[0002] Mass transfer of small parts is one of the most difficult problems to be solved to reduce production costs. For example, in the production process of micro LED displays, millions of chips must be placed in minutes to meet demand and reduce production costs. Current pick-and-place machines cannot reach such a throughput, nor can they handle these tiny parts. Therefore, a means to facilitate mass transfer of small parts is needed.

[0003] It is noted that U.S. Patent Application No. 2022076983 (Patent Document 1) discloses a method including a step of transferring multiple individual components from a first substrate to a second substrate. The known method includes a step of irradiating multiple regions on an upper surface of a dynamic release layer that attaches the multiple individual components to the first substrate. Each of the irradiated regions is aligned with a corresponding one of the individual components. The irradiating step induces plastic deformation in each of the irradiated regions of the dynamic release layer that simultaneously releases at least some of the individual components from the first substrate.

[0004] It is further noted that EP 3911130 (Patent Document 2) provides a transfer method for transferring a viscous functional material onto a receiving substrate. This method provides a plate having a cavity surface containing cavities. Respective portions of the viscous functional material within respective zones of the cavities are heated by supplying power having a time-dependent magnitude to respective ones of a plurality of individually addressable heater elements. Furthermore, heat-induced gas generation causes the functional material to transfer from the cavities onto the receiving substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application No. 2022076983 [Patent Document 2] European Patent No. 3911130 Summary of the Invention [Problem to be solved by the invention]

[0006] According to a first aspect of the present disclosure, an improved deposition apparatus for depositing components on a substrate is provided. According to a second aspect of the present disclosure, an improved deposition method is provided for depositing components on a substrate. [Means for solving the problem]

[0007] The improved deposition apparatus according to a first aspect comprises a substrate holder, a workpiece carrier, a power supply, and a support module. The substrate holder is provided with a concave substrate support surface for holding a substrate. The concave substrate support surface has exhaust channels to be evacuated so that the substrate is biased against the concave substrate support surface. The component carrier has a component carrier surface facing the concave substrate support surface for supporting a component to be deposited on the substrate. The component carrier includes a resistive heater layer for inducing thermal expansion within the component carrier to move the component carrier surface toward the concave substrate support surface. The power supply is configured to generate a deflection pulse, which is a pulse of power to the resistive heater layer that provides a heat flux to induce thermal expansion. The support module is configured to support the component carrier and may additionally serve to electrically connect a power source to the resistive heater layer.

[0008] In some embodiments, the support module constrains the component carrier on both lateral sides. Even if the component carrier has a substantially uniform coefficient of thermal expansion throughout its depth, the component carrier tends to bend toward the substrate support surface carrying the substrate thereon, since the support module will prevent deformation in the opposite direction along with the component carrier surface of the component carrier. In some examples, the support module has a slightly convex surface to support the component carrier when the support module is at room temperature.

[0009] In some embodiments, the component carrier has a first layer with a relatively low thermal expansion coefficient on the side closer to the support module and a second layer with a relatively high thermal expansion coefficient on the side closer to the substrate holder. This enhances thermally induced deflection of the component carrier. Even if the component carrier is fixed to the support module on only one side, the component carrier, along with its component carrier surface, can bend toward the substrate holder due to the heat flux from the resistive heater layer. Note that this can also be achieved with a one-sidedly mounted component carrier having a single layer or multiple layers with approximately the same thermal expansion coefficient, provided that a temperature gradient is induced in the thickness direction of the component carrier. An advantage of the latter embodiment is that the component carrier assumes a flat shape when the temperature gradient in the thickness direction of the component carrier is reduced to zero, even if the component carrier is not yet completely cooled.

[0010] In summary, the resistive heater layer acts to thermally induce deformation of the component carrier so that the component carrier surface with components thereon is moved toward the substrate holder with the substrate. However, the resistive heater layer additionally acts to thermally treat materials in thermal contact with the component carrier surface, examples of which are described in more detail below. With this in mind, one embodiment of a deposition apparatus is provided in which the component carrier includes a thermal insulation layer on a side of the resistive heater layer facing away from the component carrier surface. The thermal insulation layer does not affect the flow of heat from the resistive heater layer to the component carrier surface, but it retards heat flow in the opposite direction. As a result, the thermally induced deformation of the thermally deformable layer of the component carrier is delayed compared to a situation without the thermal insulation layer. This can be used to control the timing of the thermally induced deformation of the component carrier relative to the timing of the thermal treatment. The thicker the thermal insulation layer, the greater the time delay. Ceramic materials such as silicon oxide, silicon nitride, and aluminum oxide are particularly suitable for forming the thermal insulation layer because they are highly heat-resistant and effectively reduce heat flow. Depending on the required timing, the thickness of the thermal insulation layer can be selected from the range of, for example, about 0.1 microns to about 10 microns.

[0011] In some embodiments of the deposition apparatus, the component carrier is provided with a thermal insulating layer on the side supported by the support module, and this measure is advantageous for controlling the timing of the heat treatment relative to the timing of thermally inducing deformation of the component carrier.

[0012] Optionally, the support surface of the support module is provided with exhaust channels to be evacuated so as to bias the component carrier into contact with the support surface. When no power is supplied to the resistive heater layer and the resistive heater layer is at a relatively low temperature, the difference between atmospheric pressure on the component carrier surface and reduced pressure on the opposite surface of the component carrier biases the component carrier into contact with the support surface. When power is supplied to the resistive heater layer, the component carrier bends, overcoming the biasing force. In one example thereof, the support module has a peripheral portion, and the exhaust channels are evacuated at a lower pressure than the pressure prevailing in the exhaust channels in a central portion surrounded by the peripheral portion. In this example, the difference between atmospheric pressure on the component carrier surface and the further reduced pressure on the opposite surface of the component carrier prevailing in the peripheral portion presses the component carrier against the support surface at its periphery, even while the central portion of the component carrier bends toward the substrate.

[0013] In some embodiments, the support module comprises electrical contact pins in its peripheral portion configured to cooperate with electrical contact terminals of a component carrier in its peripheral portion, such that when the component carrier is placed on the support module, the difference between atmospheric pressure on the component carrier surface and a further reduced pressure on the opposite surface of the component carrier extending within the peripheral portion presses the electrical contact terminals of the component carrier against the electrical contact pins of the support module, thereby providing a secure electrical connection.

[0014] In some embodiments of the deposition apparatus, the substrate holder has a concave substrate support surface with exhaust channels to be evacuated so that the substrate is biased against the concave substrate support surface. This approach is based on the consideration that the component carrier will bend into a convex shape when flexed. When the substrate support surface has a complementary concave shape, it is ensured that the contact time between the component carrier surface and the components thereon and the substrate on the substrate support surface is substantially uniform over the entire area. This is particularly relevant for heat treating, e.g., soldering, components on the substrate surface.

[0015] As mentioned above, in some embodiments, the resistive heater layer not only serves to thermally induce deflection of the component carrier, but also serves to perform the heat treatment operation.

[0016] For example, in one embodiment of the deposition apparatus, the power supply is configured to generate a gluing pulse, which is a subsequent power pulse to the resistive heater layer to further increase the temperature of the resistive heater layer to activate the adhesive on the component carrier surface.

[0017] In another example already mentioned above, the power supply is configured to generate a soldering pulse, which is a subsequent power pulse to the resistive heater layer to further raise the temperature of the resistive heater layer to melt the solder by means of which the component will be connected to the substrate.

[0018] Again, in another example, the power source is further configured to generate a decomposition pulse, which is a power pulse having a shorter duration than the deflection pulse and a power greater than that of the deflection pulse, to decompose the adhesive bonding the component to the component carrier surface. Moreover, the component can be released from the component carrier surface even when the adhesive used has a relatively high adhesive strength. The decomposition pulse can be provided, for example, after the soldering pulse to release the component from the component carrier once the component has been soldered.

[0019] In one embodiment, the resistive heater layer includes multiple individually addressable portions for heating respective area portions of the component carrier surface. Furthermore, components can be selectively transferred. First, a deflection pulse is simultaneously applied to all portions of the resistive heater layer. Furthermore, the component carrier surface with the components thereon is pressed against the surface of the target substrate thereon. Then, soldering and deflection pulses can be applied to subsets of the addressable portions corresponding to the locations on the component carrier surface where selected components to be transferred reside. Furthermore, these selected components are bonded to the substrate, and the adhesive temporarily bonding the components to the component carrier is broken down. Upon cooling, the selected components remain bonded to the target substrate, while the remaining components are retracted by the component carrier surface to which they are still attached. Because the temperature distribution of the component carrier can be more precisely controlled, this approach can be suitable even when the substrate holder has a flat substrate support surface.

[0020] The improved method according to the second aspect comprises: providing a component carrier having a component carrier surface; Adhering a component onto a component carrier surface; placing a substrate on a concave substrate support surface of a substrate holder, with the concave substrate support surface facing the component carrier surface, and evacuating exhaust channels in the concave substrate support surface to bias the substrate against the concave substrate support surface; resistively heating the component carrier to induce thermal expansion in the component carrier, thereby moving a surface of the component carrier toward the concave substrate support surface; cooling the component carrier or allowing the component carrier to cool and moving the component carrier away from the substrate holder; Includes:

[0021] In one embodiment of the improved method, the component is adhered to the component carrier surface of the component carrier using a sample of thermally curable / processable / sensitive adhesive, examples of which are photoresist (positive or negative) or low melting point thermoplastic polymers (hot melt) such as PVP or PPC. The component carrier is then resistively heated with a bending pulse to thermally induce deformation of the component carrier, thereby causing the component carrier with its component carrier surface to bend toward the supply substrate having components thereon. The component carrier is then resistively heated with a gluing pulse, which causes a further temperature increase to thermally process the adhesive that bonds the component to the surface of the component carrier.

[0022] In some embodiments of the method, after resistively heating the component carrier to cause the component carrier, along with the component carrier surface of the component carrier, to bend toward the concave substrate support surface, the component carrier is further resistively heated to further increase the temperature of the component carrier, thereby forming a liquid phase for bonding the components to bond pads on the substrate. In one example of these embodiments, the component carrier surface is further resistively heated to increase the temperature of the component carrier surface, thereby breaking down an adhesive used to adhere the components onto the component carrier surface.

[0023] The improved method can also be used to remove existing soldered components (e.g., damaged and non-functional components) from a board, which can be achieved in the following embodiments:

[0024] At that point, a separate adhesive is applied to the surface of the component to be removed from the substrate or to the area of ​​the component carrier surface facing the component to be removed, with the separate adhesive used for this purpose having a melting temperature that exceeds the melting temperature of the adhesive and / or solder bonding the component to be removed to the substrate. A deflection pulse is then applied to the resistive heating layer to thermally induce deformation of the component carrier, resulting in the component carrier surface moving toward the component to be removed, and power is applied to the resistive heater layer to effect heat transfer that causes melting of the adhesive and / or solder bonding the component to be removed to the substrate, melting any additional adhesives along with it. After the power is removed, the adhesive cools and hardens, and the component carrier surface with the component bonded thereto, along with the hardened adhesive, recedes from the substrate before the adhesive curing and / or solder solidification joining the component to the substrate occurs.

[0025] These and other aspects of the present disclosure will be described in more detail with reference to the drawings. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram illustrating one embodiment of an improved deposition apparatus for depositing components onto a substrate. [Figure 2A] FIG. 1 illustrates a first operating state of a workpiece carrier used in the improved deposition apparatus. [Figure 2B] FIG. 10 illustrates a second operating state of the workpiece carrier used in the improved deposition apparatus. [Figure 3] FIG. 1 illustrates a first exemplary workpiece carrier. [Figure 4] FIG. 1 illustrates a second exemplary workpiece carrier. [Figure 4A] FIG. 10 illustrates a third exemplary workpiece carrier. [Figure 5A] FIG. 1 illustrates the first step of a subsequent step of an embodiment of the improved method. [Figure 5B] FIG. 10 illustrates the second step of the subsequent steps of an embodiment of the improved method. [Figure 5C] FIG. 10 illustrates the third step of the subsequent steps of an embodiment of the improved method. [Figure 5D]FIG. 10 illustrates the fourth step of the subsequent steps of an embodiment of the improved method. [Figure 5E] FIG. 10 shows the fifth step of the subsequent steps of an embodiment of the improved method. [Figure 6A] FIG. 10 illustrates another aspect of the embodiment. [Figure 6B] FIG. 10 illustrates another aspect of the embodiment. [Figure 7] FIG. 10 illustrates a step in an alternative embodiment of the improved method. DETAILED DESCRIPTION OF THE INVENTION

[0027] Like reference symbols in the various drawings indicate like elements unless otherwise indicated.

[0028] 1 shows a schematic diagram of an embodiment of an improved deposition apparatus for depositing component CMP on a substrate STR. The deposition apparatus includes a substrate holder 2, a component carrier 3, a power supply 4, and a support module 5.

[0029] The substrate holder 2 has a substrate support surface 2s for holding a substrate STR. The component carrier 3 has a component carrier surface 3s facing the substrate support surface 2s for supporting a component CMP to be deposited on the substrate. The component carrier 3 is supported by a support module 5 and includes a resistive heater layer 31.

[0030] The power supply 4 is configured to generate a power pulse, also referred to herein as a deflection pulse Pd, to the resistive heater layer 31. The deflection pulse generates heat in the resistive heater layer 31, which thermally induces a deformation of the component carrier 3, such that the component carrier surface 3s with the component CMP thereon moves towards the substrate STR on the substrate support surface 2s.

[0031] 2A and 2B show a support module 5 with a component carrier 3 in two operating states. In the first operating state shown in Fig. 2A, the component carrier 3 is at a low temperature. In the second operating state shown in Fig. 2B, the component carrier 3 is deformed due to the high temperature.

[0032] In the illustrated embodiment, the component carrier 3 includes at least a first layer 32a, closer to the support module 5, having a first thermal expansion coefficient, and a second layer 32b, closer to the substrate holder 2, having a second thermal expansion coefficient greater than the first thermal expansion coefficient. In this example, at least the first layer 32a is a wafer 32a, and at least the second layer 32b includes one or more bus bars embedded in the wafer. In this example, the wafer is a silicon wafer having a thermal expansion coefficient of 3.1 ppm / K, and the bus bars are made of copper having a thermal expansion coefficient of 17 ppm / K. When the power supply 4 supplies a deflection pulse to the resistive heater layer 31, the heat induced in the resistive heater layer 31 expands the bus bars in the second layer 32b. The first layer 32a also expands, but to a lesser extent. As a result, the component carrier 3 deflects, and thus the component carrier surface 3s of the component carrier, having the component CMP thereon, moves toward the substrate STR thereon on the substrate support surface 2s. It should be noted that this effect can also be achieved if the component carrier 3 does not have layers with different expansion coefficients, provided that the component carrier 3 is fixed to the support module 5 at both lateral edges. In that case, the desired deformation still occurs due to the integral thermal expansion of the component carrier 3. Since the component carrier 3 cannot bend in the direction toward the support module 5, the component carrier 3, together with its component carrier surface 3s, will bend toward the substrate STR. Another option for achieving the desired thermally induced deformation is to create a temperature gradient in the thickness direction of the component carrier 3, i.e., so that the temperature of the component carrier 3 decreases toward the support module 5. Even if the component carrier 3 has a uniform thermal expansion coefficient, the side facing the substrate, which experiences a higher temperature, will expand more than the side facing the support module 5, which has a lower temperature, resulting in the component carrier surface 3s moving toward the substrate. In the embodiment shown in FIG. 1, bus bars in the second layer 32b enable electrical connection between the power supply 4 and the resistive heater layer 31.

[0033] In the embodiment of Fig. 1, the support module 5 supports the component carrier 3 on both lateral sides. As shown in Fig. 1, the support module 5 comprises a peripheral portion 5p with exhaust channels 51p. During operation, the exhaust channels 51p are evacuated. At the opposite edge, the support module 5 comprises a similar peripheral portion. The difference between atmospheric pressure on the component carrier surface 3s and the pressure on the opposite surface of the component carrier, which extends into the peripheral portion, presses the component carrier against the support surface at its periphery.

[0034] The central portion of the support surface 5s of the support module 5 is also provided with an exhaust channel 51 through which exhaust air is evacuated to bias the component carrier 3 against the support surface 5s. When no power is supplied to the resistive heater layer and the resistive heater layer is at a relatively low temperature, the difference between the atmospheric pressure on the component carrier surface and the reduced pressure on the opposite surface of the component carrier biases the component carrier against the support surface. When power is supplied to the resistive heater layer, the component carrier bends, overcoming the biasing force. Typically, the pressure prevailing in the exhaust channels 51p at the periphery of the support module 5 is lower than the pressure prevailing in the exhaust channels 51 in the central portion surrounded by the peripheral portion. Even when the central portion of the component carrier is deflected by thermally induced deformation, the component carrier 3 is still firmly pressed against the periphery of the support module 5 at both its edges (or edges, if the component carrier is circular).

[0035] In the embodiment shown in Fig. 1, the support module 5 comprises electrical contact pins 52 in its peripheral portion 5p, which are configured to cooperate with electrical contact terminals 33 (see Figs. 3 and 4) of the component carrier 3 in its peripheral portion 3p (see Figs. 3 and 4). When the component carrier 3 is placed on the support module 5, the difference between atmospheric pressure on the component carrier surface and the further reduced pressure on the opposite surface of the component carrier prevailing in the peripheral portion presses the electrical contact terminals of the component carrier against the electrical contact pins 52 of the support module. Moreover, a solid electrical and mechanical connection is provided between the support module 5 and the component carrier 3. If desired, the electrical and mechanical connection can be cancelled by removing the vacuum in the exhaust channels 51 and 51p.

[0036] In the embodiment shown in FIG. 1 , the substrate holder 2 has a concave substrate support surface 2s with exhaust channels 22 to be evacuated so that the substrate STR is biased against the concave substrate support surface 2s. Furthermore, a substantially uniform contact time is ensured over the entire area between the component carrier surface 3s and the component CMP thereon and the substrate STR on the substrate support surface 2s. This is particularly relevant for thermally treating, e.g., soldering, components on the substrate surface. The difference between the pressure in the environment and the relatively low pressure prevailing in the exhaust channels of the concave substrate support surface causes the substrate to assume the curvature of the concave substrate support surface so that the thermal contact time is similar over the entire area.

[0037] Figure 3 shows a first example aspect of a component carrier 3 in one embodiment of the deposition apparatus 1. In the embodiment shown in Figure 3, the component carrier 3 has a square-shaped resistive heater layer 31 electrically connected to a bus bar in a second layer 32b having contact pins 33 that allow electrical connection with electrical contact pins (not shown) in the peripheral portion 5p of the support module.

[0038] FIG. 4 shows another embodiment, in which the component carrier 3 has a circular resistive heater layer 31 .

[0039] FIG. 4A shows another embodiment in which a component carrier 3 has carrier fingers 3a, 3b, ... 3n laterally separated from one another by gaps. The carrier fingers are fixed at a first end and have a second free end opposite the first end. Each carrier finger 3a, 3b, ... 3n has a respective heater layer portion 31a, 31b, ... 31n and a respective pair of contact terminals 33a, 33a', ... 33n, 33n' at the first end of the heater layer portion to which the heater layer portion is fixed. Additionally, the carrier fingers can be heated independently of one another to bend the carrier finger and to move the corresponding component Ca, ... Cn supported at the second end of the carrier finger toward the target surface. As with other embodiments, deflection of the component carrier fingers can be the result of differential thermal expansion of layers therein. Alternatively, or additionally, deflection can be due to temperature gradients within the carrier finger.

[0040] 5A-5E and 6A-6B illustrate an embodiment of an improved method for depositing component CMP on a substrate STR, whereby Figures 5A-5E illustrate the operating states of the component carrier 3, and Figures 6A-6B illustrate the temperature T3 (solid lines) and deflection D3 (dashed lines) of the component carrier 3 as a function of time during the execution of the method.

[0041] As shown in FIG. 5A, a component carrier 3 having a component carrier surface 3s is prepared, and the component CMP to be deposited is bonded to the component carrier. In this example, for each component to be bonded, a sample of thermally curable / processable / sensitive adhesive ADH is applied to the component carrier surface 3s of the component carrier 3. As shown in FIG. 5A, the component carrier 3 is supported by a support module 5. Additionally, the component carrier 3 is secured to the support module 5 by a pressure difference between ambient pressure and a pressure VAC1 applied within an exhaust channel 51p in a peripheral portion 5p of the support module 5. The exhaust channel 51 is also evacuated to a pressure VAC2 between the pressure VAC1 and ambient pressure, biasing the component carrier 3 against the surface 5s of the support module. FIG. 5A also shows that a substrate holder 2 carrying a temporary substrate SBC with component CMP is positioned in front of the component carrier surface 3s. The temporary substrate SBC is also shown pressed against the concave surface 2s of the substrate holder 2 by the difference between ambient pressure and a reduced pressure VAC3 prevailing within an exhaust channel 22 in the substrate holder 2. The heating rate during the deflection step S1A determines the speed at which the component carrier surface 3s approaches the components CMP on the temporary substrate SBC. In the example shown, the component carrier surface 3s deforms by 150 μm in 2 milliseconds, which corresponds to a speed of approximately 0.075 m / s. A corresponding increase in the power supplied during the deflection step S1A also allows for an increase in the speed. However, care should be taken that the deflection rate is not too high. For example, when performing this step in a few microseconds, the deflection rate may be too high and may cause damage.

[0042] In a subsequent step S1B shown in FIG. 5B, a power supply (not shown) supplies a deflection pulse Pd (from t0 to t5, see FIG. 6) to the contact pins 52. A pressure difference caused by the exhaust pressure VAC1 in the peripheral portion establishes a firm electrical connection between the electrical contact pins 52 and the electrical contact terminals 33 in the peripheral portion 3p of the component carrier 3. As a result, the resistive heater layer 31 resistively heats the component carrier. Moreover, at time t1, the thermal stress induced in the component carrier 3 is strong enough to deflect the component carrier away from the exhaust surface 5s of the support module 5. However, the component carrier 3 remains firmly pressed against the support module 5 at its periphery due to the stronger pressure difference induced by the exhaust pressure VAC1. At time t3, the component carrier 3 is deflected to such an extent that the component carrier surface 3s of the component carrier is pressed toward the component CMP on the supply substrate SBC. As shown in FIG. 6, at that time, the temperature T3 of the component carrier 3 temporarily drops.

[0043] As shown in FIG. 6, the power supply then supplies a gluing pulse Pg (from t6 to t7). Furthermore, the component carrier 3 is heated to a required temperature T AAThe adhesive ADH is resistively heated to a temperature exceeding 1000 K (S1C). In one example, the adhesive ADH is a photoresist (positive or negative). In another example, the photoresist includes a photoacid generator. Furthermore, the activation temperature of the adhesive can be modified within a larger range to a desired value for a specific application by activating the photoacid generator to different degrees determined by the duration or intensity of irradiation with optical radiation (e.g., ultraviolet radiation). Alternatively, low-melting thermoplastic polymers (hot melts) such as PVP and PPC may be used as adhesives. The temporary substrate SBC is usually cooler than the component carrier 3 when in contact, thereby acting as a heat sink. This should be taken into account by either providing more energy during the gluing pulse or by preheating the temporary substrate SBC. During the cooling period, the adhesive force between the component carrier 3 and the component CMP must be higher than the adhesive force between the component CMP and the temporary substrate SBC, so that the component CMP is pulled away from the temporary substrate SBC. When the component carrier 3 is retracted, it can be placed on the target substrate and aligned with the bond pads on the target substrate.

[0044] In the situation shown in Figure 5C, the target substrate STR is placed (S2) on the substrate support surface 2s of the substrate holder 2. The substrate support surface 2s with the substrate STR thereon faces the component carrier surface 3s. As shown in Figure 5C, the substrate STR thereon is provided with solder SD on the bond pads BP.

[0045] In a subsequent step S3A shown in Figures 5D and 6B, a deflection pulse Pd is again applied between t9 and t13 to resistively heat the component carrier 3 and thereby induce thermal expansion so that the component carrier surface 3s moves towards the substrate support surface.

[0046] Following step S3A, in step S3B, while the component carrier 3 is still in its deflected state, the power supply supplies solder pulses Ps (from t4 to t15). The component carrier 3 is then resistively heated to an elevated temperature above the soldering temperature T2 to form a liquid phase for bonding the component CMP to the bond pads (PB) on the substrate STR. The component CMP is then assembled to the bond pads PB, for example, by soldering or eutectic bonding. Alternatively, the electrical and mechanical connection between the component CMP and the bond pads PB can be achieved in this step by curing a conductive adhesive precursor. Note that the interconnect material, such as solder or a conductive adhesive, can also be already present on the component CMP itself. The pressure exerted by the deflected component carrier 3 along with the adhesive ADH helps to hold the component CMP in place while it is soldered or bonded to the substrate STR. In this way, the component CMP, for example, a micro LED display element, can be assembled with high precision in all six degrees of freedom to ensure good image quality.

[0047] In the embodiment shown in FIG. 6B, the power supply then supplies a decomposition pulse Pdc in step S3C. At the same time, the component carrier surface is further resistively heated, raising the temperature of the component carrier surface to a value above the decomposition temperature of the adhesive (ADH) still adhering the component CMP to the component carrier surface 3s. After supplying the decomposition pulse Pdc, the adhesive ADH is decomposed, so that during the cooling and retraction in step S3D, the component carrier 3 is released from the component CMP, as shown in FIG. 5E. The decomposition pulse Pdc can also be postponed until the solder connections with the substrate STR thereon are solidified, provided that the component carrier 3 is still sufficiently deflected to apply pressure to the components. Note that the decomposition pulse Pdc can have a relatively short duration, since only the adhesive in direct thermal contact with the component carrier surface 3s needs to be heated.

[0048] A decomposition pulse may also be applied after the soldering pulse to release the components from the component carrier once they have been soldered.

[0049] Once the substrate STR has cooled sufficiently, the substrate can be released from the substrate support surface 2s by removing the vacuum in the exhaust channels 22.

[0050] If desired, the vacuum in the exhaust channels 51 and 51 p can also be removed so that the component carrier 3 can be removed from the support module 5 .

[0051] It may be considered to perform the deflection, soldering, and decomposition steps in a single pulse. In this case, a single pulse of power (having a relatively high power value) supplied to the resistive heater layer 31 of the component carrier 3 provides enough energy not only to deflect the component carrier 3 but also to process the interconnect material (e.g., a precursor to solder or conductive adhesive) and to decompose the adhesive that temporarily bonds the component CMP to the component carrier surface 3s. After supplying the single pulse, the component carrier 3 cools and retracts, while the component CMP remains bonded to the target substrate STR thereon. This approach is preferable when the component to be transferred is relatively thick, e.g., >100 μm, and has a relatively low thermal conductivity, e.g., <1 W / mK.

[0052] The improved method and apparatus provide a cost-effective solution for transferring components to a target substrate. The thermal deformation of the component carrier 3, which deforms the component carrier surface 3s of the component carrier 3 toward the substrate STR thereon, is very fast and occurs in a more controllable manner than would be achievable with an electromagnetic actuator, and is cost-effective.

[0053] Furthermore, the improved method and apparatus allow for the integration of various production steps, including pick-and-place, thermal curing, and release, within a single system. This reduces complexity and significantly increases component assembly throughput. The only throughput limitation comes from aligning the substrate holder 2, substrate, and component carrier 3. With an alignment time of approximately 0.5 seconds, the improved apparatus and method can fully assemble over 1,000,000 micro-components per second. Moreover, the alignment time per component is negligible.

[0054] It should also be noted that the additional pressure exerted on the components by the component carrier 3 during the soldering (or curing) step ensures that the transferred components are perfectly flush with the target substrate STR.

[0055] Provided that the components are temporarily glued to the component carrier surface 3s, the component carrier 3 can be used continuously, which is in stark contrast to PDMS stamps, which are prone to wear and lead to yield issues.

[0056] If it is detected that a component CMPx provided on the temporary substrate SBC does not meet the quality requirements, this component can easily be prevented from being glued to the component carrier 3 in an alternative step S1A' as shown in Figure 7. In this case, no adhesive is provided at the location of the defective component CMPx on the component carrier surface 3s. In that case, when continuing with the steps shown in Figures 5B and 5C, the defective component CMPx remains on the temporary substrate SBC, while the remaining components are transferred.

[0057] If it is true that a component already bonded to the target surface appears to be malfunctioning, the component can be removed and replaced with an improved device as follows: A droplet of thermal adhesive is deposited on the component carrier surface 3s opposite the malfunctioning component, and the component carrier surface 3s with the thermal adhesive thereon is pressed against the malfunctioning component by applying a deflection pulse. A soldering pulse is then applied to melt the solder bonding the defective component to the substrate. The thermal adhesive should have a decomposition temperature higher than the melting point of the solder bonding the component to the substrate. An additional actuator can be provided to retract the support module 5 with the component carrier 3 with the malfunctioning component bonded thereon before the solder begins to solidify again.

[0058] The improved apparatus can then be used to bond the replacement part to the target substrate. This can be achieved by selectively picking up the replacement part from the temporary substrate. This can be done in a similar manner to that shown in Figure 7. However, in this case, step S1A' is used to selectively transfer the replacement part to a part carrier 3. The replacement part can then be transferred to an empty position on the substrate STR thereon, in the steps shown in Figures 5C, 5D, and 5E.

[0059] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single component or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. Reference signs in the claims are not to be interpreted as limiting the scope.

Claims

1. A deposition device (1) for depositing parts (CMP) on a substrate (STR), comprising: a substrate holder (2) having a concave substrate support surface (2s) for holding the substrate (STR), the concave substrate support surface (2s) having an exhaust channel (22) to be evacuated so that the substrate (STR) is biased against the concave substrate support surface (2s); a component carrier (3) having a component carrier surface (3s) facing the concave substrate support surface (2s) for supporting the component to be deposited on the substrate, the component carrier (3) comprising a resistive heater layer (31) for thermally inducing deformation of the component carrier (3) to move the component carrier surface (3s) towards the concave substrate support surface (2s); a power supply (4) configured to generate a deflection pulse (Pd), which is a power pulse to the resistive heater layer (31) for thermally inducing deformation; a support module (5) for supporting said component carrier (3); A deposition device (1) comprising:

2. 2. The deposition device (1) according to claim 1, wherein the component carrier (3) comprises at least a first layer (32a) having a first thermal expansion coefficient on a side closer to the support module (5) and a second layer (32b) having a second thermal expansion coefficient higher than the first thermal expansion coefficient on a side closer to the substrate holder (2).

3. 3. The deposition apparatus (1) of claim 2, wherein the at least a first layer (32a) is a wafer (32a) and the at least a second layer (32b) comprises one or more bus bars (32b) embedded in the wafer.

4. 4. The deposition device (1) according to claim 1, 2 or 3, wherein the support module (5) supports the component carrier (3) on a single lateral side.

5. 4. The deposition device (1) according to claim 1, 2 or 3, wherein the support modules (5) constrain the component carriers (3) on both lateral sides.

6. A deposition apparatus, wherein the component carrier (3) is provided with a thermal insulation layer on the side supported by the support module (5).

7. 7. The deposition apparatus of claim 1, wherein the component carrier comprises a thermal insulating layer on a side of the resistive heater layer facing away from the component carrier surface.

8. 8. The deposition device (1) according to claim 1, wherein in the peripheral part (5p) of the support module (5), the support surface (5s) is provided with exhaust channels (51p) to be evacuated at a pressure lower than the ambient pressure.

9. 9. The deposition device (1) according to claim 8, wherein the support module (5) comprises electrical contact pins (52) in the peripheral part (5p) of the support module configured to cooperate with electrical contact terminals (33) of the component carrier (3) in the peripheral part (3p) of the component carrier.

10. 10. The deposition device (1) according to any one of claims 1 to 9, wherein the support surface (5s) of the support module (5) is provided in a central part with an exhaust channel (51) to be evacuated so as to bias the component carrier (3) against the support surface (5s) at a pressure lower than the ambient pressure but higher than the pressure evacuating the exhaust channels (51p) in the peripheral part (5p).

11. 11. The deposition apparatus (1) according to any one of claims 1 to 10, wherein the power supply (4) is configured to generate a gluing pulse (Pg), which is a subsequent power pulse to the resistive heater layer (31) to further increase the temperature of the resistive heater layer to activate an adhesive (ADH) on the component carrier surface.

12. 12. The deposition apparatus (1) according to any of claims 1 to 11, wherein the power supply (4) is configured to generate a soldering pulse (Ps), which is a subsequent power pulse to the resistive heater layer (31) to further increase the temperature of the resistive heater layer for processing an interconnect material, such as a solder or a conductive adhesive precursor, with which the component (CMP) will be connected to the substrate (STR).

13. 13. The deposition apparatus (1) according to any one of claims 1 to 12, wherein the power source (4) is further configured to generate a decomposition pulse (Pdc), which is a power pulse having a duration shorter than that of the deflection pulse and a power greater than that of the deflection pulse, in order to decompose an adhesive (ADH) that bonds the component (CMP) to the component carrier surface (3s).

14. 9. The deposition apparatus (1) of claim 8, wherein the resistive heater layer (31) comprises a plurality of individually addressable portions for heating respective areas of the component carrier surface.

15. 15. The deposition device (1) according to any one of claims 1 to 14, wherein the component carrier has carrier fingers (3a, 3b, ... 3n) fixed at a first end and having a second free end opposite the first end, the carrier fingers being laterally separated from one another by gaps.

16. 1. A method for depositing a part (CMP) on a substrate (STR), comprising: Providing a component carrier (3) having a component carrier surface (3s); Steps (S1A, S1B, S1C) of bonding said component (CMP) onto said component carrier surface (3s), a step (S2) of placing the substrate (STR) on a concave substrate support surface (2s) of a substrate holder (2), the concave substrate support surface (2s) facing the component carrier surface (3s), and evacuating an exhaust channel (22) in the concave substrate support surface (2s) to bias the substrate (STR) against the concave substrate support surface (2s); (S3A) resistively heating the component carrier to induce thermal expansion within the component carrier, thereby moving the component carrier surface (3s) towards the concave substrate support surface; a step (S4) of cooling the component carrier or allowing it to cool and moving the component carrier (3) away from the substrate holder (2); A method comprising:

17. A step (S1) of bonding the component (CMP) onto the component carrier surface (3s) of the component carrier (3), providing (S1A) a sample of thermally curable / processable / sensitive adhesive (ADH) on a component carrier surface (3s) of a component carrier (3); a step (S1B) of resistively heating the component carrier with a deflection pulse (Pd) to thermally induce a deformation of the component carrier, wherein the component carrier at the deflection pulse (Pd) bends with the component carrier surface (3s) of the component carrier towards a supply substrate (SBC) having components thereon; Subsequently, a step (S1C) of selectively heating the component carrier with a gluing pulse (Pg), the gluing pulse causing a further temperature increase to heat-treat the adhesive for bonding the component to the surface of the component carrier; 17. The method of claim 16, comprising:

18. 18. The method according to claim 16 or 17, wherein after the step (S3A) of resistively heating the component carrier to cause the component carrier together with its component carrier surface (3s) to bend towards the substrate support surface (2s), the component carrier is further resistively heated to further increase the temperature of the component carrier, thereby forming a liquid phase of the substrate (S3B) for bonding the component (CMP) to a bond pad (PB) on the substrate (STR).

19. 19. The method according to claim 18, wherein after the bonding step (S3B), the component carrier surface is further resistively heated with a decomposition pulse to increase the temperature of the component carrier, thereby decomposing (S3C) the adhesive (ADH) used to bond the component (CMP) onto the component carrier surface (3s).

20. applying another adhesive to a surface of the component to be removed from the substrate or to an area of ​​the component carrier surface facing the component to be removed, the another adhesive having a melting temperature that exceeds the melting temperature of the adhesive and / or solder joining the component to the substrate; applying power to the resistive heating layer while subsequently moving the component carrier surface toward the component, resulting in a transfer of heat that causes melting of the adhesive and / or solder joining the component to the substrate and melting of the additional adhesive; removing the power supply while allowing the additional adhesive to cool and harden, and retracting the component carrier surface, to which the component is bonded by the hardened additional adhesive, from the substrate before the adhesive and / or solder that bonded the component to the substrate hardens or solidifies; 20. The method of any of claims 16 to 19, comprising:

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